The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 20, 2010

Filed:

Jun. 29, 2005
Applicants:

Takashi Kikukawa, Tokyo, JP;

Hajime Utsunomiya, Tokyo, JP;

Hiroshi Shingai, Tokyo, JP;

Tatsuya Kato, Tokyo, JP;

Inventors:

Takashi Kikukawa, Tokyo, JP;

Hajime Utsunomiya, Tokyo, JP;

Hiroshi Shingai, Tokyo, JP;

Tatsuya Kato, Tokyo, JP;

Assignee:

TDK Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/24 (2006.01);
U.S. Cl.
CPC ...
Abstract

In an optical information medium having an information bearing surface having projections and depressions and/or capable of forming recorded marks, a functional layer is added. The information borne on the information bearing surface can be read by using reading light of a wavelength longer than 4NA·Pwherein Pis the minimum size of the projections and depressions or the recorded marks and NA is the numerical aperture of a reading optical system, setting the power of the reading light within such a range that the functional layer does not change its complex index of refraction, and irradiating the reading light to the information bearing surface constructed by the functional layer or to the information bearing surface through the functional layer or to the functional layer through the information bearing surface. The medium enables reading at a high resolution beyond the diffraction limit.


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